5” Pansy build thread

[turbominij]

Little time cutting the meat of out 2 of the eccentric rods today and putting nice curves on the ends with my new bull nosed end mill!!!

They are rather rough cuts currently but will clean up easily enough when I’m done

No point getting a perfect finish when 50%is being cut away

[turbominij]

Spent today drilling and prepping the rods and eccentric straps so I can fit them together have a center spigot in there so they locate properly and always go back in the same spot when the come apart I’m yet to mark them as pairs

The need shaping at the far endto to the strap still you can see the intended shap in the scribe lines

They also need fettling and tinkering with out but we are getting there with the first two






Popped the frames together today and found the paint has made the crank axle box’s a little snug so crank is a little snug will shave the paint off the horns I think as have a bit of over spray on them home site should have masked them
Still trying to get ready for test fitting the eccentric rods so I can rotate the crank



Stupidly I fitted the rods upside down and to the wrong straps🤦‍♂️ double fail!!!!

Will refit them tomorrow and split the forks so they can actually be tested still huge steps forward

[turbominij]

Hi all
Popped this part of the valve gear together and I’m worried I’ve got something wrong
The valve only moves enough to cover and uncover the rear port it doesn’t move back far enough to uncover the front one.
I Don’t want to carry on with the other two rods if somethings wrong with them

I’m thinking it might be the eccentrics are not positioned properly
Any tips for roughly setting them just to prove things are close enough to being right

[chris vine]

Whatever is wrong or right, the movement should be approx symmetrical about the ports.
Can you adjust the position of the valve on its rod to achieve this??
Chris

[turbominij]

No there is no adjustment left in the rods or linkage so I’m thinking they might be to long or threaded bit is not long enough

The rods are not a part I made they already existed when I brought it and haven’t checked the lengths thinking about it so probably a good idea

il measure them tomorrow and confirm they are correct as per drawings this could account for them only uncovering the rear and the front not being seen
I guess the other thing is the valves being too fat again I haven’t checked the measurements on them


So long as rods are both the same length(not adjusted)
The ports would only be even if the eccentrics were places 180 apart otherwise they wouldent be even I’m right in saying yes?

[turbominij]

Ok so a bit of working out testing lengths of thing and setting the eccentric discs so they are opposite each other
and progress I can get the valve to sit in the middle and evenly open ports but they don’t open them very much.

How much of the port should be open ? At the end of each stroke?

[turbominij]

After hitting problems testing things yesterday with insufficient valve movement I set about today to try and improve things

The improvements came from finishing making the lift links and fitting them to the reverser shaft in doing so I noticed it was moving as the crank was rotated meaning it was all binding so………

Opened up the expansion link ends by squaring them off so the dies would move all the way to the end
Rounded the die block spaces to give some more room

Rounded and shaped the rods as it turns out the bell shape at the end is critical for clearance at the full forward and full revers of the valve gear
The net result of all the fettling is

And have made massive improvements i previously only had the ports cracking open i now have the ports half open on each end of the movement with adjustment available to time it later if needed

Still got some more work to do to get it fitting nicer but this morning it wouldn’t have worked and I was worried I done something wrong now it looks like it will work and things can only improve

Proper chuffed with that improvement !!




Yes I no the expansion link straps are upside down it’s because I have no grub screws in #4 eccentric currently as it looks rough so I have ordered some new ones

So I’m using 1 and 2 for my testing.

[turbominij]

Been a couple of weeks since I’ve had any time
The third and 4th eccentric strap were drilled and had their fixing studs and center studs fitting ready to take the rods

The 3 and 4 eccentric rod blanks were drilled to match

3 and 4 eccentric rods had some meet taken out of them on the ban saw

then eccentric rod 3 had it’s critical cuts to thickness done ,No3 now just needs shaping which is less critical

[turbominij]

Got the last of the rods down to thickness and the steps put in


Then had an hour spare tonight and cut and filed the profile in to them roughly

Forgott to pick up the filing dies to do the round ends lo so will have to do them another night
Another stint on them sorting out the ends and the valve gear will be complete!!

Then to make them look pretty!!!

[turbominij]

Roughly filed the rods ready for a trial fit before draw filling and final shaping using some filing dies I made






Turned the cross head bolts one is fitted by this point





Then drawfiled the poor machining marks off the cross head guide bars and refitted it all
Including packing the piston glands and bolting them down need to remove the top bars again to fit an oil cup



test fitted one of the connecting rods and all seems to work ok

[turbominij]

Final shaping to the eccentric rods and a little repair to on as was a bit flat on one end

Once painted you won’t tell it’s there

[turbominij]

Bit more filing and polishing of the eccentric rods and fitting to the straps



Filing out the expansion links to a square end to get maximum movement



Only bits left of the valve gear now are clean up one lift link and make the bottom expansion link pivot pins then fit it all together again 🥳

[turbominij]

Popped the valve gear together today
Rather pleased with the initial fit needs a bit more work fettling thing so it all move nicely as it’s a little stiff and a few bits bind but for a first attempt at it all together it will do nicely also need a new temp grub screw for the rocker as lost one


In revers it’s a little tight on the lift links need a bit more space cut in to the lift links to give some clearance for the eyes to pass

Trying to get full forward it binds slightly on the die block closest to the leaver
so a little more rounding of the ends and rounding of the die block corners and it should be good

[turbominij]

Today saw pansys come together a little more all gaskets fitted to the cylinder block all glands packed

All valve gear and Crank rods fitted
And a wheel thread sealed lightly on to give something to turn it all over by









I have one tight spot which I think is a blemish in one of the bores as was there all the time with out the other bits fitted but other than that it all moves freely so will probably continue for now and regime them when I have it all apart again

It moves nicely between forward and reverse I’m very please with the die lock and expansion links are so smoth

Need to try and set the valve gear next and sort suspension out so I can turn it all over

[turbominij]

Little update
Made and fitted the suspension for the center axle

shimmed the crank rods so they are a snug fit on the big endsAnd there is no free play

Removed the tight spot on the cross heads ,there was a little bur on on so once that was removed and a small shim fitted it all moved freely

Fitted the eccentric straps again and found another tight spot on one so fitted a shim to give a slightly looser fit when tightened up I didn’t want to try opening it out as it will ware anyway.

Fitted the weigh shaft and in full forward we have a clearance issue to the eccentric straps so that’s the next job to deal with


Also started working out now to do the reverser reach rod

[turbominij]

Tiny bit done today
shaped the bits to make the fork for reverser last 4 of the suspension stays made last night



Today fettled the eccentrics rods a little they are now much smoother

Fitted the Alan head grub screws in eccentrics replacing slot head ones for a much better feel when doing them up.


Made a fitting for the cylinder block to fit to my air line


Need to fit the reversing leaver next

So I can set all the eccentric positions Not long now and we could be running on air with a little luck